I’m not sure whats happening with the watts usage,my card doesn’t have that,it only says N/A,also my laptop doesn’t have a LED indicator for the dGPU but there is a way to know if the card is really powered on or off,
if you execute this command (assuming you card is on 01:00:00,if not check lspci)
watch cat /sys/bus/pci/devices/0000:01:00.0/power/runtime_status
It can be active or suspended,activate means is powered on,otherwise it says suspended.
If it says activated in integrated mode,the only think I can think of is TLP preventing the dGPU from power off as I mention above,go to /etc/tlp.conf and change
SOUND_POWER_SAVE_ON_AC from 0 to 1,save and reboot,now the dGPU should say suspended.
You can also veritfy the power usage on the laptop with TLP,so you just have to do a
watch sudo tlp-stat -b
and check where it says /sys/class/power_supply/BAT0/current_now,this show the power usage when its in battery or charging.
In my case,Integrated mode in battery consumes 380-450 mA,when the dGPU is activated it consumes between 750-900 mA.